Antioxidant activity of polyphenols in licorice beans (Glycyrrhiza glabra L.)

Introduction. The worldwide trend towards green technologies has increased interest in the development and use of natural, highly-efficiency and inexpensive plant antioxidants to replace existing synthetic ones. Purpose of the study. study of the composition of polyphenols in licorice beans and their antioxidant activity. Methods. The content of polyphenols was investigated in ethanol extracts of licorice beans by the Folin - Ciocalteu method, identification of polyphenols was carried out using HPLC, the assessment of antioxidant activity was carried out in three ways: the ability to trap free radicals, the reducing ability, and antioxidant activity. Results. the total content of polyphenols in the EEBS averages 37.17 μg gallic acid equivalent. HPLC identifiedglabrin, catechin, rutin, lycochalcon A, and ellagic acid. The antioxidant properties of EEBS were evaluated in vitro. It was shown that EEBS reached the maximum absorption of DPPHradicals at a concentration of 1.6 mg/ml. At an initial concentration of 0.2 mg/ml, the effect of EEBS in trapping DPPH radicals was slightly more than 35% compared to control, and grew along with the increase in EEBS concentration, bearing a pronounced dose-dependent character up to 81.0% at a maximum concentration of 1.6 mg/ml. Critical volume of EEBS required for 50% degradation of DPPH. is 0.6 mg/ml. The reducing ability of EEBS with butyryl hydroxytoluene (BHT) as a reference standard showed that it has a significant (p<0.05) dose-dependent effect, from an initial concentration of 36.0 μg/ml, to the final concentration at 320 μg/ml, the difference absorption was 0.45 (from 0.11 to 0.56). In addition, the reducing ability of EEBS was very close to that of BHT at the same concentration. Conclusion. Licorice beans, in addition to licorice root, can be used as a powerful biologically active source of natural antioxidants.

licorice, beans, polyphenols, antioxidant activity